DESCRIPTION: The major aims of the investigators' ongoing research have been: (a) to identify the early emergence and stability of children's hostile behaviors and their associated psychophysiological responses to behavioral challenges, which are possible risk factors for cardiovascular diseases in adulthood; and (b) to specify their determinants and consequences. During the current grant project, the following cross-sectional relationships are being tested in 135 pre- and post-pubertal children: (a) the influence of sociodemographic characteristics (being black American versus white American, male versus female, and middle versus lower social class) on the development of children's predispositions, including hostile cognitions, low social support from family and friends, and hemodynamic responses to psychological stress; (b) the influence of children's predispositions on key biological risk factors including central body fat, elevated resting pressure, high insulin levels, and low--high density lipid- cholesterol; and (c) the influence of children's predispositions and biological risk factors on left ventricular mass index. Because the current project was reduced in length from four to three years, in the next project period current cross-sectional study will be completed by testing an additional 25 children. Then the associations described above will be evaluated further by recruiting an additional 45 pre-pubertal children, retesting all children (N=88) who were initially prepubertal at various points in the pubertal transition, and retesting all children who were initially postpubertal and who completed echocardiographic assessments (N=44). In this way, the project can test the proposed longitudinal relationships can be tested among sociodemographic characteristics and risk factors in children, describe the effects of development and of puberty specifically on the extent of longitudinal relationships, and further understanding of the development of high risk trajectories from adolescence to young adulthood.